Computing areas under the Normal Curve with the TI-85

The program listed below will allow the user to find areas under the normal
curve for intervals ranging from -4.5 to 4.5. The results are reported
as percentages (0 to 100%) rounded to two places past the decimal (e.g.
68.29%).
The results are fairly accurate, with worst-case errors of 0.02%.

For the mathematically inclined, the algorithm simply evaluates
an eighth-degree polynomial approximation of the cumulative density function
at the two endpoints and subtracts. The polynomial approximation
is based on mutually orthogonal polynomials on [-4.5,4.5]. The truth is,
using the built in integrator on the formula for the normal curve is sometimes
faster and always more accurate; this was an interesting experiment, though.

Just enter this program in your TI-85 and run.
You can download a binary version for linking
to your calculator...

...or type in the program below.
If you type, please proofread your typing carefully; being off by just
one character will likely cause serious errors.
Note that uppercase and lowercase are NOT interchangeable.